A student began an experiment by measuring out 7.482 g of calcium chloride. A few minutes later, she measured out 4.9 g of additional calcium chloride using a different instrument. When she reports the total mass of calcium chloride, how many significant figures should she use?

The answer said it's 3. I want to know why, I though we are looking for lest precise value when add two numbers together. I saw 4.9g to be least, which should result in 2 sigfigs instead of 3